Răspuns:
a=2,5=5/2
Explicație pas cu pas:
{[(2a+3)×2+3]×2+3}×2+3=85
{..............}x2+3=85
{...}x2=82
{.....}=41
[..............]×2+3=41
[...............]*2=38
[..........]=19
(2a+3)×2+3=19
(2a+3)×2=16
(2a+3)=8
2a=5
a=5/2=2,5
verificare
{[(5+3)x2+3]x2+3}x2+3=85
{[8*2+3]*2+3}x2+3=85
{19*2+3}x2+3=85
41x2+3=85
82+3=85
85=85 adevarat, bine rezolvat
